Django Model Deprecater README

Django Model Deprecater is a library that aims to make it easier to deprecate models by raising warnings or errors when a database interaction with the model table is detected.

Currently this library is in alpha and has not been pushed to pypi because it has yet to be used in a production like environment. Once it has, the package will be pushed to pypi. For now to use this package please install like so:

$ pip install -e git+https://github.com/oreillymedia/django-model-deprecater#egg=django-model-deprecater

Use Cases

• You want to easily identify where models are being used and communicate to the team that the model should no longer be supported
• You want to begin to remove the model and want all tests that use the model to fail.

Caveats

• Since the router only knows about database interactions, it will not know about pure python usage of the model yet.

  x = SomeModel()  # But it would detect the usage once `.save()` or any other database operation is called

Usage

To use this router in Django just add these settings:

DATABASE_ROUTERS = ['django_model_deprecater.routers.DeprecatedModelRouter']
DEPRECATED_MODEL_ROUTER = {
    # Whether to allow migrate if model deprecated
    'check_allow_migrate': False,
    # Whether to allow relations if a model in the auth app is involved
    'check_allow_relation': False,
    'models': {
        # This will raise DeprecatedModelException whenever the router detects interaction with the model table
        'app.V1Thing': DeprecatedModelException,
        # This will throw a DeprecatedWarning with the given string
        'app.V2Thing': 'This model will soon be replaced by app.V3Thing'
        # This will warn with the same message you would get from DeprecatedModelException
        'app.V3Thing': 'WARN',
        # This will raise a DeprecatedModelException as well
        'app.V4Thing': 'RAISE', 
    },
}

Requirements

• Python 2.7, 3.6
• Django 1.8+, 2.0

Setup Locally

$ virtualenv ve --python=python --prompt="(django-model-deprecater)"
$ pip install -r requirements/base.txt
$ pip install -r requirements/tests.txt

Run tests

• Note: These tests require the system to either have docker or docker-machine Setup

$ tox  # Run the tests for all the environments
$ tox -e py27-django111  # Run only the tests under Python 2.7 and Django 1.11